Sonocatalyzed synthesis of 2-phenylvaleronitrile under controlled reaction conditions – A kinetic study

In the current study, kinetics of synthesis of 2-phenylvaleronitrile (PVN) was successfully carried out by selective C-alkylation of benzyl cyanide (BC) with n-bromopropane (BP) using aqueous KOH and catalyzed by TBAB under ultrasonic (300 W) assisted organic solvent-free conditions. Selective monoalkylation of benzyl cyanide has been achieved by controlling the reaction conditions and has been followed using gas chromatogram. The effects of various parameters such as agitation speed, catalyst concentration, KOH concentration, benzyl cyanide concentration, volume of water, ultrasonic frequency and temperature were studied systematically to understand their influence on the rate of the reaction. The experimental observations are consistent with an interfacial-type process. Further the kinetic results demonstrate clearly, that ultrasonic assisted phase-transfer catalysis significantly increased the reaction rate when compared to silent reactions.

Research highlights
► Efficient sonocatalyzed synthesis of 2-phenylvaleronitrile was established.
► Exclusive 2-phenylpentanenitrile can be obtained on utilizing n-bromopropane as a limiting agent.
► Rational explanations to account for the kinetic phenomena and the type of mechanism involved were outlined